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96518518 | 1 | /* |
ef1f7df9 | 2 | * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net> |
96518518 PM |
3 | * |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License version 2 as | |
6 | * published by the Free Software Foundation. | |
7 | * | |
8 | * Development of this code funded by Astaro AG (http://www.astaro.com/) | |
9 | */ | |
10 | ||
11 | #include <linux/kernel.h> | |
12 | #include <linux/init.h> | |
13 | #include <linux/module.h> | |
14 | #include <linux/netlink.h> | |
15 | #include <linux/netfilter.h> | |
16 | #include <linux/netfilter/nf_tables.h> | |
17 | #include <net/netfilter/nf_tables_core.h> | |
18 | #include <net/netfilter/nf_tables.h> | |
19 | ||
20 | struct nft_byteorder { | |
21 | enum nft_registers sreg:8; | |
22 | enum nft_registers dreg:8; | |
23 | enum nft_byteorder_ops op:8; | |
24 | u8 len; | |
25 | u8 size; | |
26 | }; | |
27 | ||
28 | static void nft_byteorder_eval(const struct nft_expr *expr, | |
29 | struct nft_data data[NFT_REG_MAX + 1], | |
30 | const struct nft_pktinfo *pkt) | |
31 | { | |
32 | const struct nft_byteorder *priv = nft_expr_priv(expr); | |
33 | struct nft_data *src = &data[priv->sreg], *dst = &data[priv->dreg]; | |
34 | union { u32 u32; u16 u16; } *s, *d; | |
35 | unsigned int i; | |
36 | ||
37 | s = (void *)src->data; | |
38 | d = (void *)dst->data; | |
39 | ||
40 | switch (priv->size) { | |
41 | case 4: | |
42 | switch (priv->op) { | |
43 | case NFT_BYTEORDER_NTOH: | |
44 | for (i = 0; i < priv->len / 4; i++) | |
45 | d[i].u32 = ntohl((__force __be32)s[i].u32); | |
46 | break; | |
47 | case NFT_BYTEORDER_HTON: | |
48 | for (i = 0; i < priv->len / 4; i++) | |
49 | d[i].u32 = (__force __u32)htonl(s[i].u32); | |
50 | break; | |
51 | } | |
52 | break; | |
53 | case 2: | |
54 | switch (priv->op) { | |
55 | case NFT_BYTEORDER_NTOH: | |
56 | for (i = 0; i < priv->len / 2; i++) | |
57 | d[i].u16 = ntohs((__force __be16)s[i].u16); | |
58 | break; | |
59 | case NFT_BYTEORDER_HTON: | |
60 | for (i = 0; i < priv->len / 2; i++) | |
61 | d[i].u16 = (__force __u16)htons(s[i].u16); | |
62 | break; | |
63 | } | |
64 | break; | |
65 | } | |
66 | } | |
67 | ||
68 | static const struct nla_policy nft_byteorder_policy[NFTA_BYTEORDER_MAX + 1] = { | |
69 | [NFTA_BYTEORDER_SREG] = { .type = NLA_U32 }, | |
70 | [NFTA_BYTEORDER_DREG] = { .type = NLA_U32 }, | |
71 | [NFTA_BYTEORDER_OP] = { .type = NLA_U32 }, | |
72 | [NFTA_BYTEORDER_LEN] = { .type = NLA_U32 }, | |
73 | [NFTA_BYTEORDER_SIZE] = { .type = NLA_U32 }, | |
74 | }; | |
75 | ||
76 | static int nft_byteorder_init(const struct nft_ctx *ctx, | |
77 | const struct nft_expr *expr, | |
78 | const struct nlattr * const tb[]) | |
79 | { | |
80 | struct nft_byteorder *priv = nft_expr_priv(expr); | |
81 | int err; | |
82 | ||
83 | if (tb[NFTA_BYTEORDER_SREG] == NULL || | |
84 | tb[NFTA_BYTEORDER_DREG] == NULL || | |
85 | tb[NFTA_BYTEORDER_LEN] == NULL || | |
86 | tb[NFTA_BYTEORDER_SIZE] == NULL || | |
87 | tb[NFTA_BYTEORDER_OP] == NULL) | |
88 | return -EINVAL; | |
89 | ||
90 | priv->sreg = ntohl(nla_get_be32(tb[NFTA_BYTEORDER_SREG])); | |
91 | err = nft_validate_input_register(priv->sreg); | |
92 | if (err < 0) | |
93 | return err; | |
94 | ||
95 | priv->dreg = ntohl(nla_get_be32(tb[NFTA_BYTEORDER_DREG])); | |
96 | err = nft_validate_output_register(priv->dreg); | |
97 | if (err < 0) | |
98 | return err; | |
99 | err = nft_validate_data_load(ctx, priv->dreg, NULL, NFT_DATA_VALUE); | |
100 | if (err < 0) | |
101 | return err; | |
102 | ||
103 | priv->op = ntohl(nla_get_be32(tb[NFTA_BYTEORDER_OP])); | |
104 | switch (priv->op) { | |
105 | case NFT_BYTEORDER_NTOH: | |
106 | case NFT_BYTEORDER_HTON: | |
107 | break; | |
108 | default: | |
109 | return -EINVAL; | |
110 | } | |
111 | ||
112 | priv->len = ntohl(nla_get_be32(tb[NFTA_BYTEORDER_LEN])); | |
113 | if (priv->len == 0 || priv->len > FIELD_SIZEOF(struct nft_data, data)) | |
114 | return -EINVAL; | |
115 | ||
116 | priv->size = ntohl(nla_get_be32(tb[NFTA_BYTEORDER_SIZE])); | |
117 | switch (priv->size) { | |
118 | case 2: | |
119 | case 4: | |
120 | break; | |
121 | default: | |
122 | return -EINVAL; | |
123 | } | |
124 | ||
125 | return 0; | |
126 | } | |
127 | ||
128 | static int nft_byteorder_dump(struct sk_buff *skb, const struct nft_expr *expr) | |
129 | { | |
130 | const struct nft_byteorder *priv = nft_expr_priv(expr); | |
131 | ||
132 | if (nla_put_be32(skb, NFTA_BYTEORDER_SREG, htonl(priv->sreg))) | |
133 | goto nla_put_failure; | |
134 | if (nla_put_be32(skb, NFTA_BYTEORDER_DREG, htonl(priv->dreg))) | |
135 | goto nla_put_failure; | |
136 | if (nla_put_be32(skb, NFTA_BYTEORDER_OP, htonl(priv->op))) | |
137 | goto nla_put_failure; | |
138 | if (nla_put_be32(skb, NFTA_BYTEORDER_LEN, htonl(priv->len))) | |
139 | goto nla_put_failure; | |
140 | if (nla_put_be32(skb, NFTA_BYTEORDER_SIZE, htonl(priv->size))) | |
141 | goto nla_put_failure; | |
142 | return 0; | |
143 | ||
144 | nla_put_failure: | |
145 | return -1; | |
146 | } | |
147 | ||
ef1f7df9 PM |
148 | static struct nft_expr_type nft_byteorder_type; |
149 | static const struct nft_expr_ops nft_byteorder_ops = { | |
150 | .type = &nft_byteorder_type, | |
96518518 | 151 | .size = NFT_EXPR_SIZE(sizeof(struct nft_byteorder)), |
96518518 PM |
152 | .eval = nft_byteorder_eval, |
153 | .init = nft_byteorder_init, | |
154 | .dump = nft_byteorder_dump, | |
ef1f7df9 PM |
155 | }; |
156 | ||
157 | static struct nft_expr_type nft_byteorder_type __read_mostly = { | |
158 | .name = "byteorder", | |
159 | .ops = &nft_byteorder_ops, | |
96518518 PM |
160 | .policy = nft_byteorder_policy, |
161 | .maxattr = NFTA_BYTEORDER_MAX, | |
ef1f7df9 | 162 | .owner = THIS_MODULE, |
96518518 PM |
163 | }; |
164 | ||
165 | int __init nft_byteorder_module_init(void) | |
166 | { | |
ef1f7df9 | 167 | return nft_register_expr(&nft_byteorder_type); |
96518518 PM |
168 | } |
169 | ||
170 | void nft_byteorder_module_exit(void) | |
171 | { | |
ef1f7df9 | 172 | nft_unregister_expr(&nft_byteorder_type); |
96518518 | 173 | } |